186 results about "Background fluorescence" patented technology

The invention provides a method for rapidly detecting wastewater pollutants by atomic fluorescence spectrometry, and belongs to the technical field of wastewater treatment.The method comprises the steps that atomic fluorescence spectrum data of a wastewater sample are collected to establish a spectrum interference matrix to characterize the spectral line overlapping condition between elements; abnormal values are recognized through statistical analysis, a spectrum outlier matrix is built, abnormal fluorescence intensity distribution is recorded, sample matrix non-characteristic fluorescence signals are measured, a background fluorescence interference matrix is built, background interference intensity is quantized, system signal change rules are continuously monitored and detected, and a signal drift tendency matrix is built to predict the signal drift tendency. A spectrum interference matrix and a background fluorescence interference matrix are processed through a spectrum analytic function, compensation factors are calculated, spectrum overlapping and background interference influences are corrected, system drift is corrected in real time, and a final wastewater pollutant concentration detection result is output, so that the technical problem of unstable detection precision caused by coupling of multiple interference factors is solved.

The invention discloses a beta-lactoglobulin fluorescent probe as well as a preparation method and application thereof, the structural formula of the probe is (C30H25N4I), the probe is combined with beta-lactoglobulin through non-covalent interaction, a fluorescence signal is triggered to be remarkably enhanced, and low-background fluorescence detection of the beta-lactoglobulin is realized. The probe has low cytotoxicity and excellent mitochondrial targeting ability, and provides a powerful tool for visualization of beta-lactoglobulin in living cells. After being combined with beta-lactoglobulin, a sample can generate obvious color change under the irradiation of an ultraviolet lamp, and the change can be used for evaluating the content of active beta-lactoglobulin in the sample, so that the rapid detection of the milk protein level in a beverage is realized. The beta-lactoglobulin fluorescent probe disclosed by the invention has a wide application prospect in the fields of biological imaging, milk protein detection, beverage quality control and the like.

The invention belongs to the technical field of microbiological detection, and discloses a composite probe for detecting salmonella enteritidis and a preparation method. The composite probe for detecting the salmonella enteritidis comprises magnetic nanoparticles FeO, wherein the surface of the magnetic nanoparticles FeO is modified with an aptamer apt which is specifically combined with the salmonella enteritidis; the surface of the long afterglow nano particle PLNPs is modified with a DNA (Deoxyribose Nucleic Acid) sequence cDNA (Complementary Deoxyribonucleic Acid) complementary with the aptamer; the aptamer apt and the complementary DNA sequence cDNA are subjected to hybridization to form a composite probe structure FeO-SEapt (at) PLNPs-cDNA (complementary deoxyribonucleic acid). The long afterglow luminescence characteristic of PLNPs (ZnGaO: Cr) is utilized, and an excitation light source is stopped before detection, so that signal acquisition completely avoids autofluorescence of a sample matrix, background fluorescence interference is thoroughly eliminated, and the signal-to-noise ratio is remarkably improved.

The invention discloses an automatic focusing method and system of a cell slide scanner, and relates to the related field of optical equipment focusing technology.The method comprises the steps that a slide is previewed and scanned, a multi-mode preview image and physical height sensing data are synchronously collected and preprocessed, and then the pre-processed image is obtained; the multi-modal preview image and the corresponding height data are input into a pre-training focus prediction model, a focusing strategy graph aligned with a slide coordinate space is output, and the graph comprises the predicted optimal focus offset, the focusing function recommendation identifier, the focus verification confidence coefficient and the search radius of each view point; according to the focusing strategy graph, a final focus is determined through feedforward positioning, limited verification and conditional adjustment, a scanner objective table is controlled to carry out formal scanning at the final focus position, and a complete scanning image of the cell slide is collected. The problems that a traditional focusing method is long in time consumption and poor in adaptability to complex samples with low contrast, high background fluorescence and scratch pollution are solved, and the adaptive capacity of the focusing process is improved.

The invention belongs to the technical field of analysis and detection, and particularly relates to a beta-galactosidase response type hemicyanine near-infrared fluorescent probe, a preparation method thereof and application of the beta-galactosidase response type hemicyanine near-infrared fluorescent probe as a tumor organ imaging probe. The near-infrared fluorescent probe provided by the invention takes a water-soluble hemicyanine skeleton as a fluorophore, so that the biocompatibility of the near-infrared fluorescent probe is improved; based on the principle that beta-galactose can be selectively cut by beta-galactosidase, a galactose structure with a self-leaving group is used as a response group, selective quick response to the beta-galactosidase is achieved, and high sensitivity to the beta-galactosidase is shown. The near-infrared fluorescent probe provided by the invention can emit near-infrared fluorescence with long wavelength, has lower background fluorescence and good penetration depth, and can be directly used for detecting organoids containing the matrigel without eliminating the matrigel, so that the organoids are prevented from being damaged or additional experimental variables are prevented from being introduced in the process of eliminating the matrigel.

A line-scan confocal scanning light-field microscopic imaging apparatus (10) and method. Said apparatus comprises: a microscope (100), a target biological sample being placed on a stage of the microscope (100); an excitation optical path (200), which is used for outputting a line-shaped light source for exciting fluorescence of the target biological sample; a line-scan hardware optical path (300), which is used for performing multi-dimensional scanning of the line-shaped light source to obtain a scanned light-field image; a microlens array (400), which is used for light-field modulation of the line-shaped light source to obtain a line-shaped light field; a camera (500), which is used for performing three-dimensional imaging on the basis of the line-shaped light field to obtain a three-dimensional image; and a control system (600), which is used for controlling the line-scan hardware optical path (300) and the camera (500) to execute a line-scan confocal action, so that the number of pixel rows exposed simultaneously at a same moment is consistent with a sample region illuminated by the line-shaped light source, so as to separate a sample fluorescence signal and a background fluorescence signal of the target biological sample, and, on the basis of the scanned light-field image and the three-dimensional image, generate a three-dimensional microscopic image with background fluorescence removed for the target biological sample. Therefore, the problem of background fluorescence in a scanning light-field microscopy system is solved.

The invention provides a multi-focus excitation confocal fluorescence microscopic imaging flow cytometry screening method. The method is characterized in that a laser beam generates three laser beams through a spatial light modulator, and the three laser beams are coherently superposed in a focal plane of a microscope objective to generate a two-dimensional optical lattice light field. And after the other laser beam is shaped by the cylindrical lens, linear laser optical tweezers are realized through the microscope objective, cells to be detected in an imaging detection area of the micro-flow chip are captured, and accurate active optical control on the rotation angle of the cells to be detected is realized. In a cell rotation process, a two-dimensional optical lattice light field rapidly scans in a focal plane at different angles, and a fluorophore in the cell is excited to generate a fluorescence signal. The confocal pinhole array installed at the position conjugate with the focal plane eliminates background fluorescence, a high-spatial-resolution fluorescence image of a three-dimensional structure in the cell is obtained, and cell screening is achieved. The method provided by the invention has the characteristics of high detection rate, high accuracy and the like, and has wide application prospects in the research fields of biology, medicine and life science.

The invention discloses an aggregation-induced emission-metal-organic framework probe which is prepared by taking copper hydroxide as a metal center and 1, 1, 2, 2-tetra (4-carboxybenzene) ethylene as an organic ligand through a one-pot solvothermal method. The invention discloses a method for detecting diazinon by using a fluorescence sensing system constructed based on the aggregation-induced emission-metal-organic framework probe. The aggregation-induced emission-metal-organic framework probe is extremely low in background fluorescence, background signal interference during diazinon detection can be reduced, and sensitivity is improved. Meanwhile, enzyme mediation is introduced to serve as a controllable recognition element, specific and sensitive detection of diazinon is achieved, and the detection limit is 0.14 ng.mL <-1 >. The aggregation-induced emission-metal-organic framework probe disclosed by the invention shows the advantages of high sensitivity, high selectivity, quick response, stability, simplicity and convenience in operation and the like in diazinon detection, and has a wide application prospect.

The invention relates to a biosensor capable of efficiently responding to vanillin, and belongs to the technical field of bioengineering. An aldehyde response transcription factor YqhC from Escherichia coli and a promoter element PyqhD regulated by the aldehyde response transcription factor YqhC are used for establishing a vanillin response RFP report system, a yqhC gene is subjected to semi-rational design, a mutation library is constructed through saturated mutation, vanillin is used as a substrate, and a non-background fluorescence response, a non-background fluorescence response function and a non-background fluorescence response function are obtained by screening response concentration and response threshold values. The YqhC mutant has a wider substrate detection range (0-10 mM) and higher response strength (167 times), and is named as YqhC-V18. The biosensor containing a vanillin response element (YqhC-V18) and a fluorescent protein report element (RFP) is further obtained, and can be applied to detection of a sample containing vanillin, or screening of a vanillin production strain, or regulation and control of the production process of vanillin.

The invention discloses a red fluorescent silicon nanodot as well as a preparation method and application thereof. The method comprises the following steps: S1, weighing sulforhodamine 101, adding ultrapure water for dissolving, then adding N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, uniformly stirring, transferring the obtained mixture into a reaction kettle, and heating for reaction; and S2, after the reaction is finished, cooling to room temperature, purifying the obtained product by using a silica gel chromatographic column, eluting by using an eluent, collecting the eluent, and finally, freeze-drying to obtain the red fluorescent silicon nanodots. Compared with common blue-green fluorescence, red fluorescence emission has deeper tissue penetrability and background fluorescence interference resistance; the silicon nanodot provided by the invention not only has excellent light stability and high quantum yield, but also has characteristics similar to lipophilic cations, and can specifically target mitochondria in living cells; in addition, the silicon nanodots also show excellent imaging ability in zebrafish embryos and juvenile fish bodies.

The invention belongs to the technical field of microsphere preparation, and particularly relates to a magnetic microsphere and a preparation method thereof. Through cooperation of the cross-linking agent and the monomer, the polystyrene microsphere with good swelling and shrinking performance is provided; in the swelling process, introduced divalent and trivalent iron ions can be coordinated with carboxyl groups of the microspheres and are uniformly dispersed in the microsphere structure; then, by adjusting the pH value, the iron ions react to generate ferroferric oxide distributed in the microspheres and on the surfaces of the microspheres, and in the shrinkage process of the microspheres, the density of aromatic rings is reduced by the ferroferric oxide based on space occupation of the ferroferric oxide, so that background fluorescence is reduced, and the signal-to-noise ratio and sensitivity of fluorescence detection are improved. In addition, ferroferric oxide has an optical shielding effect and can be mutually matched with a coating layer arranged outside the microsphere, so that the fluorescence intensity of the polystyrene material magnetic microsphere is jointly reduced.

The invention aims to provide a photodynamic therapy power control method and system, and relates to the technical field of photodynamic therapy. The method comprises the following steps: setting an initial value of output power of an excitation light source, and starting the excitation light source to perform photodynamic therapy operation on a therapy area; collecting the total fluorescence emission spectrum of the treatment area in real time, and obtaining the fluorescence intensity of the photosensitizer and the fluorescence intensity of the photoproduct according to the total fluorescence emission spectrum; and adjusting the output power of the excitation light source according to the photosensitizer fluorescence intensity and the light product fluorescence intensity. The background fluorescence emission spectrum is calculated through the output power of the excitation light source, so that the fluorescence intensity of the photosensitizer and the fluorescence intensity of the photoproduct are accurately separated, and the progress and the effect of photodynamic therapy are accurately evaluated; by dynamically adjusting the output power of the excitation light source, the output power of the light source can be matched with the real-time response state of the treatment area, and the accuracy and robustness of power control are improved.

The invention discloses a power system equipment operation risk intelligent identification and early warning system. The system comprises an environmental parameter acquisition module, a passive ultraviolet fluorescence detection module, an active ultraviolet laser excitation module, a background fluorescence analysis and dynamic threshold calculation module, an abnormal signal confirmation module, an intelligent determination module and a closed loop verification and alarm module. Environment characteristic indexes are calculated by monitoring temperature, humidity and air pressure in real time; collecting and analyzing a natural ultraviolet fluorescence signal, actively emitting ultraviolet laser to excite environmental fluorescence response, and adaptively calculating a dynamic anomaly judgment threshold value; abnormal signals are accurately confirmed by utilizing multi-dimensional feature combination and feature space analysis, and corona discharge and line discharge are distinguished through intelligent judgment; and finally, carrying out automatic secondary verification positioning on the visible light image, and automatically generating a discharge early warning signal. The system has the characteristics of high sensitivity, strong interference resistance and high intelligent degree, and the discharge detection reliability is effectively improved.

The invention belongs to the technical field of talc, and provides a method for detecting fluorescent substances in talc raw ore, which comprises the following steps: S1, carrying out ball milling on the talc raw ore in a ball mill, sieving to obtain sieved powder, and adding deionized water into the sieved powder to obtain slurry; s2, adding the slurry into the mixture to enable the pH value of the slurry to be 5, stirring, and standing in a water bath for 2-3 hours to obtain a first precipitate; s3, adding a thiourea-ascorbic acid solution into the first precipitate to obtain a second precipitate; and S4, carrying out secondary ball milling on the second precipitate, and spreading the second precipitate in an enamel plate to detect whether the talc raw ore contains the fluorescent substances or not. The hydrochloric acid can dissolve quartz and mica to avoid generation of background fluorescence or quenching effect, and the nonionic surfactant polyethylene glycol can be adsorbed on the surface of the mineral to reduce interfacial tension, so that the hydrochloric acid is easier to infiltrate tiny pores, the pit defect caused by local over-corrosion is reduced, the pickling uniformity is improved, and the detection sensitivity is improved.

The present invention provides a large Stokes shift near-infrared fluorescent probe for detecting HClO, its preparation method and biological imaging application, belonging to the field of bioanalysis technology. Based on the strategy of modifying the substituents at the 3,6 positions of xanthene, the present invention constructs a large Stokes shift near-infrared fluorescent probe for specifically recognizing HClO. Optical experiments show that the emission wavelength of the probe for detecting HClO is 776 nm, the Stokes shift reaches 148 nm, with strong selectivity, high sensitivity, and a detection limit as low as 4.95 nM, which can greatly reduce the interference of background fluorescence in biological imaging applications. The fluorescent probe of the present invention has almost no cytotoxicity and can be applied to the detection and imaging of HClO in living cells MCF-7 and rat liver tissues, with a tissue penetration depth of 140 μm.

The application relates to establishment and application of an isobutyraldehyde biosensor and belongs to the technical field of bioengineering. yqhD The RFP report system responding to isobutyraldehyde is established, the yqhC gene is rationally designed, a mutant library is constructed through random mutation by using error-prone PCR, isobutyraldehyde is used as a substrate, and through screening of response concentrations and response thresholds, a YqhC mutant without background fluorescence response, with a wider substrate detection range (0-5 g / L) and higher response intensity (24 times) is obtained, and the YqhC mutant is named YqhCm9. The isobutyraldehyde response element (YqhCm9) and the fluorescent protein report element (RFP) are used to construct a high-efficiency and specific isobutyraldehyde biosensor, real-time monitoring of an isobutyraldehyde production process and screening of an isobutyraldehyde production strain can be carried out.

The invention discloses a viscosity-sensitive near-infrared two-region fluorescent probe, which can perform fluorescence imaging in a near-infrared II region, can lighten tumor tissues and distinguish normal tissues from tumor tissues based on viscosity response, and is used for in-vivo positioning of cancers. The invention further discloses a preparation method and application of the probe. The preparation method is easy to operate and mild in reaction condition. Compared with a clinical dye molecule ICG, the fluorescent probe disclosed by the invention has more excellent light stability and can be used for long-time in-vivo imaging of organisms. The emission wavelength of the fluorescent probe reaches an NIR-II region, so that the interference of a biological background fluorescent signal can be effectively reduced.

The application discloses an up-conversion fluorescent probe, an isoniazid detection method and a portable isoniazid detection sensor and belongs to the field of biological detection. The up-conversion fluorescent probe is composed of lanthanide-doped core-shell structure up-conversion nanoparticles subjected to acid pickling treatment and p-dimethylaminobenzaldehyde, wherein the core particle diameter of the up-conversion nanoparticles is 25.85-28.85 nm, and the shell layer thickness is 0.98-1.38 nm. The lanthanide-doped core-shell structure up-conversion nanoparticles are used as an energy donor, and the p-dimethylaminobenzaldehyde is used as a specific recognition molecule, and ratio-type fluorescence detection is realized through an inner filter effect. Isoniazid reacts with DMAAB to generate a Schiff base, which causes fluorescence quenching at 475 nm and no change in 655 nm fluorescence, so that the fluorescence color changes from blue to red. Due to the near-infrared excitation characteristics of the up-conversion nanoparticles, the up-conversion nanoparticles are not easily disturbed by background fluorescence, so that rapid quantitative detection of isoniazid in whole blood is realized, and the detection limit is as low as 2.4 μm. The application is simple in operation, strong in anti-interference and suitable for clinical individualized drug monitoring.

A near-infrared fluorescent molecular probe with the "ESIPT + AIE" effect for detecting hydrogen sulfide has the following structural formula: #imgabs0# The aqueous solution of this fluorescent molecular probe is sensitive to the concentration of H2S, with a detection limit (LOD) of 0.83 μM (S / N = 3), showing high sensitivity; the maximum emission wavelength is 713 nm, having advantages such as strong tissue penetration, low background fluorescence interference, and little damage to cells / tissues, which is conducive to realizing the detection and / or imaging of endogenous H2S content; the linear detection range is 0 - 30 μmol / L, with a wider quantitative range and a broader application range.

The invention provides an intelligent tongue picture feature identification method and system, relates to the technical field of biomedical detection, and aims to avoid confusion of subsequent signal processing caused by environmental noise by accurately identifying and eliminating ambient light interference with fixed frequency through fast Fourier transform analysis after a pre-processed original composite light signal is obtained. When the target lingual surface area shifts to cause dynamic change of the background fluorescence signal, the preset adaptive filtering algorithm can accurately identify and reject the changed background fluorescence digital signal values of the tongue picture in real time. The step-by-step and self-adaptive processing strategy ensures that the removal of ambient light interference and the correction of the background fluorescence signal are mutually independent and do not interfere with each other, thereby avoiding the generation of internal processing conflicts and calculation artifacts described in the background technology, and obtaining highly pure and accurate tongue picture fluorescence digital signals. The accuracy and reliability of tongue picture feature identification are remarkably improved, and a more reliable data basis is provided for oral health detection.

The present application relates to a kind of high efficiency response vanillin biosensor, belong to the field of bioengineering technology.The present application utilizes aldehyde response transcription factor YqhC of escherichia coli ( Escherichia coli ) origin and the promoter element of the regulated P yqhD Establishment of RFP report system of vanillin response, to yqhC Gene semi-rational design is carried out, and mutant library is constructed by saturation mutation, with vanillin as substrate, by screening response concentration and response threshold, obtain no background fluorescence response, with wider substrate detection range (0-10 mM), and response intensity is higher (167 times) YqhC mutant, it is named YqhC-V18.Further, the biosensor containing vanillin response element (YqhC-V18) and fluorescent protein report element (RFP) is obtained, which can be applied to detect vanillin-containing sample, or screen vanillin production strain, or regulate vanillin production process.

An endoplasmic reticulum-targeted long-wavelength fluorescent probe for detecting hydroxyl free radicals, and its preparation method and application. The structure of the fluorescent probe is shown in Formula I. The present invention also provides a method for preparing the fluorescent probe and its application in hydroxyl free radical detection. The fluorescent probe provided by the present invention can sensitively and specifically detect hydroxyl free radicals in the long analytical wavelength region of 640 nm. It also has the advantages of selectively targeting the endoplasmic reticulum, low biological background fluorescence signal, minimal photodamage to biological samples, good biocompatibility, and easy preparation and use. It has great application prospects in the fields of chemistry, biology, medicine, etc.

The invention discloses a self-adaptive fluorescent dark background removal method, device and equipment and a medium, and relates to the technical field of image processing, and the method comprises the steps: obtaining a mask of a fluorescent image for a target sample; performing large-size low-pass filtering smoothing processing on the fluorescence image to obtain a background layer image; subtracting the background layer image from the fluorescence image to obtain a weak background fluorescence image; based on the mask, extracting a non-mask region from the weak background fluorescence image as a background noise region image; performing image filling on a mask region in the background noise region image to obtain a pure background image; smoothing the pure background image; and subtracting the pure background image after smooth processing from the weak background fluorescence image to obtain a corrected target image. The method does not need to pre-store or pre-collect background data, can adaptively estimate and deduct complex backgrounds including internal noise of samples, remarkably improves the signal-to-noise ratio and quantitative accuracy, and solves the problems that a traditional method is tedious in operation, poor in adaptability and incomplete in denoising.

The invention discloses a near-zero background fluorescence sensor based on polydopamine functionalized MXene as well as a preparation method and application of the near-zero background fluorescence sensor, and belongs to the technical field of universal biosensing. The sensor comprises a polydopamine functionalized MXene material and a quantum dot-aptamer fluorescent probe which is accurately coupled by click chemistry in a ratio of 1: 1. The detection method is characterized in that a target object is utilized to induce the probe to desorb from the surface of a material, and a supernatant containing the free probe is physically separated from a material precipitate through centrifugal separation, so that background fluorescence interference is almost completely eliminated. According to the invention, ultra-sensitive detection of aflatoxin B1 is realized, and the detection limit of AFB1 in complex matrixes such as corn flour is as low as 0.27 mu g / kg. All components of the platform can be modularly and independently stored for a long time, the platform can be directly applied to detection of various micromolecular mycotoxins without optimization by replacing aptamers, and the platform has high sensitivity, high stability and high universality.

The invention belongs to the technical field of chrysin detection, and particularly relates to a dual-emission fluorescent molecularly imprinted polymer as well as a preparation method and application thereof. The method comprises the following steps: preparing carbon dots with different emission wavelengths; carrying out amination modification on the carbon dots; and preparing the dual-emission fluorescent molecularly imprinted polymer. The method also comprises the following steps: respectively adding the dual-emission fluorescent molecularly imprinted polymer into chrysin solutions with different known concentrations, carrying out fluorescence quenching reaction, and establishing a standard curve according to the linear relationship between the detected fluorescence intensity and the corresponding concentration of the chrysin solution; adding the dual-emission fluorescent molecularly imprinted polymer into a solution of a to-be-detected product, and carrying out fluorescence quenching reaction to obtain fluorescence intensity; and calculating the concentration of chrysin in the solution to be detected according to the standard curve. The preparation method is used for solving the technical problems that in the prior art, a single-emission fluorescent molecularly imprinted polymer has defects in the aspects of sensitivity, background fluorescence interference resistance in a complex environment and the like in the detection process.

The application discloses a double-line ratio fluorescent competitive immunochromatographic detection device and a preparation method and application thereof, and relates to the technical field of immunochromatographic detection.The detection device comprises a double-specificity recognition unit mixed-labeled quenched fluorescent probe, a background fluorescent material and a solid phase substrate, the solid phase substrate is provided with a T line on which a target object binding ligand is immobilized and a C line on which a quality control ligand is immobilized; and the application also provides application of the detection device in detection of exogenous harmful substances.The application solves the technical problem of low detection sensitivity of the existing method, and adjusts the binding amount of the probe on the T line and the C line through an immune competition reaction, adjusts the quenching degree of the background fluorescence based on an internal filter effect, takes (T line quenched fluorescent signal / background fluorescent signal) / (C line quenched fluorescent signal / background fluorescent signal) as a quantitative signal, and takes the C line to participate in ratio calculation to improve the detection sensitivity, so that the application is suitable for high-sensitivity qualitative and quantitative detection of small molecule compounds and the detection sensitivity is improved.

The invention discloses a microscopic determination method for fiber micro-plastics in a textile aqueous solution, and relates to the technical field of environmental pollutant detection.The method comprises the steps that a water sample is collected; preparing a Nile red staining solution; adding the prepared nile red staining solution into a water sample and carrying out fluorescent staining on the water sample; filtering the water sample subjected to fluorescence dyeing by using a trace glass suction filtration device with a glass fiber filter membrane; washing the glass fiber filter membrane with an acetone solution, and washing the glass fiber filter membrane with third-stage water for multiple times; taking down the washed glass fiber filter membrane, and drying the glass fiber filter membrane in a vacuum oven; and placing the dried glass fiber filter membrane on a microscope objective table, observing fluorescent substances by using a fluorescence microscope, measuring the size and counting. The method has the effects of effectively eliminating the interference of background fluorescence and non-fiber micro-plastics, greatly reducing the omission ratio of the fiber micro-plastics, reducing the determination cost, not needing large instruments, being simple to operate and less in time consumption, and effectively improving the determination efficiency.

An analytical method of and system for monitoring cell status whereby excitation energy is focused to an excitation cytometry volume in a cell sample to fluoresce first and second fluorophores of a cell. Fluorescence signals from the first and second fluorescing cell fluorophores are directed to a detection subsystem. A first peak in fluorescence intensity for the first fluorophore is detected as is a second peak in fluorescence intensity for the second fluorophore. The fluorescence signals are processed to identify when the first and second peaks occur substantially simultaneously indicating the presence of a cell at the excitation cytometry volume instead of background fluorescence and in response, the cellular status of the cell is measured using the intensity of the levels of the first and second peaks.

The invention relates to the technical field of biological medicine, in particular to a TREM-1 targeted fluorescent molecular probe as well as a preparation method and application thereof, and discloses a fluorescent molecular probe named as' TREM-1 targeted fluorescent molecular probe as well as a preparation method and application thereof '. The invention aims to solve the problems of large molecular weight, poor pharmacokinetic performance, limited tissue penetration, high imaging background and poor imaging timeliness of the existing antibody fluorescent probe. The probe comprises a TREM-1 targeting module (TDM), a near-infrared fluorescence reporter group, a dark quenching group and a conformational sensitive connecting arm (CSL). The fluorescence of the probe is quenched before the probe is combined with TREM-1, and after the probe is combined with a target spot, TDM specific binding induces CSL conformation rearrangement, so that a reporter group and a quenching group are spatially separated, fluorescence resonance energy transfer (FRET) is relieved, and fluorescence activation is realized. According to the invention, rapid, high-contrast and low-background fluorescence imaging of atherosclerotic plaques is realized, and the probe is small in molecular size, strong in tissue penetrability and rapid in-vivo clearing.

The invention discloses an enzyme-activated fluorescent molecular precursor as well as a preparation method and application thereof. The enzyme-activated fluorescent molecular precursor has a chemical structure as shown in a formula I which is described in the specification. The invention develops an enzyme-activated fluorescent molecular precursor which can be used for real-time imaging of tumors by targeting exogenous enzyme to the tumors and specifically activating a probe at the tumors; according to the invention, the exogenous enzyme is introduced as an activation trigger, and normal cells do not have the exogenous enzyme, so that the problem of co-expression of the endogenous enzyme in non-tumor tissues can be avoided, background fluorescence signals can be reduced to the greatest extent, and the imaging specificity and accuracy are remarkably improved.